US20120029366A1 - Blood pressure detection apparatus and blood pressure detection method - Google Patents

Blood pressure detection apparatus and blood pressure detection method Download PDF

Info

Publication number
US20120029366A1
US20120029366A1 US13/191,584 US201113191584A US2012029366A1 US 20120029366 A1 US20120029366 A1 US 20120029366A1 US 201113191584 A US201113191584 A US 201113191584A US 2012029366 A1 US2012029366 A1 US 2012029366A1
Authority
US
United States
Prior art keywords
pressure
blood pressure
waveform
blood
change
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US13/191,584
Other languages
English (en)
Inventor
Toshihiko Yokoyama
Osamu Tochikubo
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Seiko Epson Corp
Yokohama City University
Original Assignee
Seiko Epson Corp
Yokohama City University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Seiko Epson Corp, Yokohama City University filed Critical Seiko Epson Corp
Assigned to PUBLIC UNIVERSITY CORPORATION YOKOHAMA CITY UNIVERSITY, SEIKO EPSON CORPORATION reassignment PUBLIC UNIVERSITY CORPORATION YOKOHAMA CITY UNIVERSITY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: YOKOYAMA, TOSHIHIKO, TOCHIKUBO, OSAMU
Publication of US20120029366A1 publication Critical patent/US20120029366A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
    • A61B5/021—Measuring pressure in heart or blood vessels
    • A61B5/022—Measuring pressure in heart or blood vessels by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers
    • A61B5/0225—Measuring pressure in heart or blood vessels by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
    • A61B5/6813—Specially adapted to be attached to a specific body part
    • A61B5/6824—Arm or wrist

Definitions

  • the blood pressure may be non-invasively measured by an auscultatory method or an oscillometric method.
  • the artery When externally applying pressure equal to or higher than the maximal blood pressure to an artery, and gradually decreasing the applied pressure, the artery produces vibrations in the audible region (Korotkoff's sound) within a specific pressure range.
  • the auscultatory method determines the applied pressure when the Korotkoff's sound is produced to be the maximal blood pressure, and determines the applied pressure when the Korotkoff's sound stops to be the minimal blood pressure.
  • the oscillometric method utilizes a phenomenon in which the dynamic properties of an arterial wall nonlinearly change relative to externally applied pressure.
  • the diameter and the volume of a blood vessel change with each heartbeat.
  • the change in volume differs depending on the pressure inside the blood vessel (blood pressure) and the externally applied pressure, but shows significant nonlinearity with respect to the internal-external pressure difference (tube law).
  • blood pressure blood pressure
  • tube law internal-external pressure difference
  • the applied pressure and the change in volume of the blood vessel are recorded at the same time during the above process to determine the maximal blood pressure, the mean blood pressure, and the minimal blood pressure.
  • JP-A-2006-280485 discloses a method that easily obtains a pulse waveform that allows direct detection of the pulse waves from a living body using a pulse wave detection means provided with a blood pressure detection strain sensor. Since the pulse waves have wavelength characteristics with a notch, the pulse waves can be clearly distinguished from noise using a band-pass filter or the like, and the maximal blood pressure and the minimum blood pressure can be accurately detected by utilizing the pulse waves.
  • a blood pressure detection apparatus comprising:
  • a press mechanism that applies pressure to a blood vessel by pressing a living body, and can gradually decrease the pressure
  • a pressure sensor that detects a change in pressure of the blood vessel caused by a change in the pressure applied by the press mechanism
  • a blood pressure calculation section that determines the pressure applied by the press mechanism when a given waveform pattern appears in a waveform that indicates a change in pressure of the blood vessel to be a maximal blood pressure, determines the pressure applied by the press mechanism when the waveform has a maximum amplitude to be a mean blood pressure, and calculates a minimal blood pressure using the maximal blood pressure and the mean blood pressure.
  • a blood pressure detection method comprising:
  • determining the pressure applied to the blood vessel when a given waveform pattern appears in a waveform that indicates a change in pressure of the blood vessel to be a maximal blood pressure determining the pressure applied to the blood vessel when the waveform has a maximum amplitude to be a mean blood pressure, and calculating a minimal blood pressure using the maximal blood pressure and the mean blood pressure.
  • FIG. 1 is a view illustrating a state in which a blood pressure detection apparatus is attached to a wrist.
  • FIG. 2 is a view illustrating a state in which a blood pressure detection apparatus is attached to a wrist.
  • FIG. 3 is a view illustrating the details of a press mechanism.
  • FIG. 4 is a view illustrating the configuration of a pressure sensor.
  • FIG. 5 is a view illustrating the details of a control-display section.
  • FIG. 6A is a view illustrating an oscillometric waveform
  • FIG. 6B is a view illustrating a differential waveform
  • FIG. 6C is a view illustrating a pressure signal waveform.
  • FIG. 7 is a view illustrating an oscillometric waveform and a pressure waveform thereof.
  • FIGS. 8A and 8B are views illustrating an oscillometric waveform and a pressure waveform thereof.
  • FIG. 9 is a view illustrating an oscillometric waveform and a differential waveform thereof.
  • FIG. 10 is a view illustrating a systolic waveform pattern included in an oscillometric waveform.
  • FIGS. 11A to 11F are views illustrating a systolic waveform pattern included in an oscillometric waveform.
  • FIG. 12 is a flowchart illustrating the entire operation (process) according to one embodiment of the invention.
  • FIG. 13 is a view illustrating a systolic waveform pattern included in an oscillometric waveform according to a modification.
  • JP-A-2006-280485 a change in volume of the blood vessel with each heartbeat and the applied pressure are recorded during the entire process when applying pressure and decreasing the applied pressure, and features corresponding to the systolic phase, the mean value, and the diastolic phase are extracted from the change in volume to determine the systolic blood pressure, the mean blood pressure, and the diastolic blood pressure.
  • the blood pressure is defined as the value in the origin of the aorta.
  • an error occurs by about 7.5 mmHg. Therefore, it is necessary to maintain the measurement site at the height of the heart during the measurement. Accordingly, it is necessary to maintain the measurement site at the height of the heart for several tens of seconds during normal blood pressure measurement.
  • a humerus-type sphygmomanometer or a wrist-type sphygmomanometer currently on the market are normally used several times a day (e.g., morning, daytime, and night).
  • Several embodiments of the invention may provide a blood pressure detection apparatus and a blood pressure detection method that can reduce the time required for blood pressure measurement.
  • a blood pressure detection apparatus comprising:
  • a press mechanism that applies pressure to a blood vessel by pressing a living body, and can gradually decrease the pressure
  • a pressure sensor that detects a change in pressure of the blood vessel caused by a change in the pressure applied by the press mechanism
  • a blood pressure calculation section that determines the pressure applied by the press mechanism when a given waveform pattern appears in a waveform that indicates a change in pressure of the blood vessel to be a maximal blood pressure, determines the pressure applied by the press mechanism when the waveform has a maximum amplitude to be a mean blood pressure, and calculates a minimal blood pressure using the maximal blood pressure and the mean blood pressure.
  • the inventors of the invention found by experiments that the applied pressure (pressure applied by the press mechanism) when a given waveform pattern appears in the waveform that indicates a change in pressure of the blood vessel corresponds to the maximal blood pressure. Therefore, the pressure applied by the press mechanism when a given waveform pattern is observed can be determined to be the systolic blood pressure (maximal blood pressure) by merely determining the presence or absence of the given waveform pattern instead of determining the change in volume of the blood vessel during the entire pressure application process. This makes it possible to reduce the measurement time as compared with a related-art blood pressure determination method.
  • the given waveform pattern may be a waveform that indicates pulse waves that include a first maximum value, and a second maximum value that is obtained when the pressure applied by the press mechanism is lower than that when the first maximum value is obtained, the second maximum value being larger than the first maximum value.
  • the inventors found by experiments that the applied pressure when a waveform that indicates pulse waves that include a first maximum value, and a second maximum value when the pressure applied by the press mechanism is lower than that when the first maximum value is obtained, the second maximum value being larger than the first maximum value, is measured as the given waveform pattern corresponds to the maximal blood pressure. This makes it possible to easily detect the presence or absence of the given waveform pattern, and reduce the measurement time as compared with a related-art blood pressure determination method.
  • the press mechanism may gradually open an artery from an occlusion state.
  • the inventors found by experiments that the given waveform pattern occurs when an artery is gradually opened from an occlusion state. Specifically, the given waveform pattern occurs by causing the press mechanism to apply pressure that occludes the artery, and then gradually decrease to the pressure so that the artery is opened. This makes it possible to easily provide a blood pressure detection apparatus that can reduce the measurement time as compared with a related-art blood pressure determination method.
  • the press mechanism may gradually occlude an artery from an open state.
  • the artery may be a radial artery.
  • the radial artery is present at a shallow position from the body surface. Since the radius is present right under the radial artery, the pressure can be applied to the radial artery by the press mechanism without being dispersed. Therefore, the blood pressure can be more reliably detected by occluding and opening the radial artery using the press mechanism.
  • a blood pressure detection method comprising:
  • determining the pressure applied to the blood vessel when a given waveform pattern appears in a waveform that indicates a change in pressure of the blood vessel to be a maximal blood pressure determining the pressure applied to the blood vessel when the waveform has a maximum amplitude to be a mean blood pressure, and calculating a minimal blood pressure using the maximal blood pressure and the mean blood pressure.
  • the applied pressure pressure applied to the blood vessel
  • the applied pressure when a given waveform pattern appears in the waveform that indicates a change in pressure of the blood vessel corresponds to the maximal blood pressure. Therefore, the applied pressure when a given waveform pattern is observed can be determined to be the maximal blood pressure by merely determining the presence or absence of the given waveform pattern instead of determining the change in volume of the blood vessel during the entire pressure application process. This makes it possible to reduce the measurement time as compared with a related-art blood pressure determination method.
  • FIGS. 1 and 2 are views illustrating a state in which a blood pressure detection apparatus according to one embodiment of the invention is attached to a wrist.
  • FIG. 1 is an external side view
  • FIG. 2 is a cross-sectional view.
  • a blood pressure detection apparatus 2 includes a press mechanism 10 , a pressure sensor 12 , and a control-display section 14 .
  • the press mechanism 10 applies an external pressure that causes a radial artery (artery) 16 to produce an oscillometric waveform 18 (see FIG. 6A ).
  • the press mechanism 10 applies pressure to a blood vessel by pressing a living body, and can gradually decrease the pressure.
  • the pressure sensor 12 measures a change in volume with each heartbeat as a change in pressure, converts the change in volume into an electrical signal, and transmits the electrical signal to the control-display section 14 .
  • the control-display section 14 executes a blood pressure calculation algorithm using the resulting oscillometric signal, and displays the results.
  • the control-display section 14 transmits a control signal that controls the pressure applied to the radial artery 16 to the press mechanism 10 .
  • the control-display section 14 and the press mechanism 10 are attached to the wrist using a wrist belt 29 that is formed of a flexible plastic or the like, the wrist belt 29 including open ends, and a fastener means (e.g., hook-and-loop fastener (Velcro fastener (registered trademark))) that fastens the ends.
  • a fastener means e.g., hook-and-loop fastener (Velcro fastener (registered trademark)
  • the artery (radial artery 16 ) is present in the wrist 20 at a shallow position (i.e., at a depth of 3 to 4 mm from the body surface).
  • a radius 22 is present right under the radial artery 16 , so that the pressure applied to the body surface is directly applied to the radial artery 16 without being dispersed. Therefore, the wrist 20 is suitable for blood pressure measurement.
  • FIG. 3 is a view illustrating the details of the press mechanism 10 .
  • the press mechanism 10 includes a motor 24 , a pump 26 , an expansion section 28 , and a housing 31 that houses each unit.
  • the motor 24 is controlled based on the control signal transmitted from the control-display section 14 via a control signal line 30 .
  • the pump 26 that is driven by the motor 24 supplies air (air from the outside in this example) to the expansion section 28 .
  • the expansion section 28 thus presses the pressure sensor 12 against the surface of the wrist 20 from the body surface (side where the radius 22 is present), so that pressure can be applied to the radial artery 16 through a body tissue 34 .
  • the expansion section 28 is formed by welding three bag-shaped disks so that the expansion height is 10 mm and the bottom has a radius of 10 mm, for example.
  • the motor 24 has a cylindrical shape having a diameter of 5 mm and a length of 10 mm.
  • the pump 26 has a cylindrical shape having a diameter of 5 mm and a length of 5 mm.
  • FIG. 4 is a view illustrating the configuration of the pressure sensor 12 .
  • the pressure sensor 12 includes a detection section 36 , a pressure-electrical signal converter 38 , and a shield 40 .
  • the radial artery 16 changes in volume due to the externally applied pressure and the blood pressure with each heartbeat.
  • the change in volume is detected by the detection section 36 through the body tissue 34 .
  • the detection section 36 is filled with an incompressible fluid, and accurately transmits the change in volume detected through the fluid to the pressure-electrical signal converter 38 as a change in pressure.
  • the pressure-electrical signal converter 38 reads the change in pressure as a change in resistance or the like, converts the change in pressure into an electrical signal, and transmits the electrical signal to the control-display section 14 via a pressure signal line 42 .
  • the amount of fluid in the detection section 36 is managed so that the fluid has dimensions of 15 ⁇ 30 ⁇ 2 mm, for example.
  • the upper side of the detection section 36 i.e., the side of the detection section 36 opposite to the side that comes in contact with the body tissue 34 ) is secured on the shield 40 so that a change in pressure can be utilized to a maximum extent.
  • the pressure-electrical signal converter 38 can detect a pressure range including a normal human blood pressure range.
  • the pressure-electrical signal converter 38 may have a detection range of 50 KPa or less.
  • FIG. 5 is a view illustrating the details of the control-display section 14 .
  • the control-display section 14 includes a capacitor 48 , an amplifier 50 , A/D converters 52 and 54 , and a CPU 56 (a blood pressure calculation section).
  • the pressure signal output from the pressure sensor 12 is input to the control-display section 14 via the pressure signal line 42 .
  • the control-display section 14 utilizes the pressure signal as two pieces of information for two different processes. Specifically, the pressure signal is used as a signal that indicates a change in volume (i.e., oscillometric signal). A DC component (direct-current component) is removed from the pressure signal by the capacitor 48 . The resulting signal is amplified by the amplifier 50 by a factor of 100, for example, converted into a digital signal by the A/D converter 52 , and input to the CPU 56 via a signal line 58 .
  • the pressure signal from the pressure sensor 12 is branched from the pressure signal line 42 , converted into a digital signal by the A/D converter 54 , and input to the CPU 56 via a pressure signal line 60 .
  • a blood pressure calculation section determines the pressure when a given waveform pattern appears in the waveform of the pulse waves obtained from the pressure sensor 12 when the artery is gradually opened from an occlusion state to be a systolic blood pressure (maximal blood pressure), and determines the pressure when the waveform has the maximum amplitude to be a mean blood pressure.
  • the blood pressure calculation section calculates the minimal blood pressure (diastolic blood pressure) from the maximal blood pressure and the mean blood pressure. It is known that the systolic blood pressure, the mean blood pressure, and the diastolic blood pressure satisfy the following relational expression.
  • the diastolic blood pressure is calculated by the following expression.
  • Diastolic blood pressure (3 ⁇ mean blood pressure ⁇ systolic blood pressure)/2
  • the blood pressure calculation section included in the blood pressure detection apparatus 2 is implemented by causing the CPU 56 to execute a given program.
  • FIGS. 6A to 6C are views illustrating a standard blood pressure determination algorithm by the oscillometric method according to one embodiment of the invention.
  • FIG. 6A illustrates an oscillometric waveform 18 (peak points of each waveform) obtained when the CPU 56 has performed a waveform process (e.g., noise removal) on a pulse waveform detected by the pressure sensor 12 when externally applying a pressure waveform 44 (see FIG. 6C ).
  • the pressure waveform 44 is also detected by the pressure sensor 12 , input to the CPU 56 via the pressure signal line 60 , and recorded together with the oscillometric waveform 18 .
  • a change in volume with a single heartbeat is about several tens of mmV. Since the signal is amplified by the amplifier 50 by a factor of 100, the signal is detected as a change by 2 to 3 V.
  • a differential waveform 46 (see FIG. 6B ) is obtained by differentiating the oscillometric waveform 18 .
  • the differential waveform 46 is obtained by a difference method that calculates the difference between each peak value of the oscillometric waveform 18 and the adjacent value.
  • the pressure of the pressure signal waveform 44 corresponding to the positive maximum value of the differential waveform 46 corresponds to the maximal blood pressure
  • the pressure of the pressure signal waveform 44 corresponding to the negative maximum value of the differential waveform 46 corresponds to the minimal blood pressure.
  • the maximal blood pressure is determined to be 120 mmHg
  • the minimal blood pressure is determined to be 90 mmHg.
  • FIGS. 7 , 8 A, and 8 B are views illustrating an oscillometric waveform according to one embodiment of the invention, and a pressure waveform thereof.
  • FIG. 7 corresponds to the oscillometric waveform 18 and the pressure signal waveform 44 illustrated in FIG. 6 .
  • FIG. 8A is an enlarged view of the first half of the waveforms illustrated in FIG. 7 (i.e., an area including the systolic blood pressure)
  • FIG. 8B is an enlarged view of an area enclosed by a dotted line in FIG. 8A so that a systolic waveform pattern 64 (given waveform pattern) is clearly observed.
  • the blood pressure pulse waveform changes across the systolic waveform pattern 64 (see waveforms A, B, C, D, and E).
  • the waveform C differs from the waveforms A, B, D, and E, and the systolic waveform pattern 64 can be easily identified.
  • a maximum value among a plurality of maximum values (two maximum values in FIG. 8B ) that precedes the other maximum value(s) in time series (i.e., when a higher pressure is applied by the press mechanism 10 ) is larger than the succeeding maximum value(s) in time series (i.e., when a lower pressure is applied by the press mechanism 10 ).
  • a maximum value among a plurality of maximum values that precedes the other maximum value(s) in time series is smaller than the succeeding maximum value(s) in time series (i.e., when a lower pressure is applied by the press mechanism 10 ).
  • the relationship between the plurality of maximum values of the waveform C differs from (is the reverse of) that of the waveform B. Therefore, the systolic waveform pattern 64 can be determined based on whether or not the relationship between the maximum values of the waveform has changed.
  • FIG. 9 is a view illustrating an oscillometric waveform according to one embodiment of the invention, and a differential waveform thereof.
  • the method of extracting the systolic waveform pattern 64 is described in more detail below.
  • the differential waveform 46 illustrated in FIG. 9 is obtained by differentiating the oscillometric waveform 18 , and includes a significant systolic waveform pattern 64 .
  • the above difference method may be used instead of the differentiation method.
  • large noise is normally superimposed on the differential waveform 46
  • the differential waveform 46 is normally used after removing noise (smoothing the waveform). For example, the sum of three successive signal values is calculated, and divided by the number of pieces of data (moving average method). In this case, the phase must be restored after the process.
  • a, b, c, and d indicate points where the value of the oscillometric waveform 18 becomes a maximum among points where the slope of a smoothed waveform 62 obtained by smoothing the differential waveform 46 is 0.
  • the waveform B satisfies the relationship “h 1 >h 2 ”
  • the waveform C satisfies the relationship “h 3 ⁇ h 4 ” in the example illustrated in FIG. 9 .
  • the relationship between the plurality of maximum values of the waveform C differs from (is the reverse of) that of the waveform B. Therefore, it can be easily determined that the waveform C includes the systolic waveform pattern 64 .
  • the systolic waveform pattern 64 can be normally detected by the above method. However, a clear systolic waveform pattern 64 may not be obtained from the temporal relationship between the decompression speed and the blood pressure pulse waveform. This applies to a case where the waveform D is directly generated from the waveform B without generating the waveform C (see FIG. 9 ), for example. In this case, the pressure (applied pressure) detected by the pressure sensor 12 which corresponds to the waveform B, and the pressure (applied pressure) detected by the pressure sensor 12 and corresponds to the waveform D are determined, and the median value therebetween is determined to be the systolic blood pressure. Therefore, the blood pressure can be determined without measuring the entire oscillometric waveform 18 (i.e., the advantage of the invention is not impaired).
  • FIG. 10 is a view illustrating the systolic waveform pattern 64 included in the oscillometric waveform 18 according to one embodiment of the invention.
  • the oscillometric waveform 18 has a specific waveform (systolic waveform pattern 64 ) when the pressure (applied pressure) detected by the pressure sensor 12 is (almost) equal to the systolic blood pressure 68 of the pressure signal waveform 44 .
  • the pressure (applied pressure) i.e., systolic blood pressure 68
  • the pressure (applied pressure) detected by the pressure sensor 12 which corresponds to the systolic waveform pattern 64 indicates the maximal blood pressure.
  • the applied pressure corresponding to the maximum value of the systolic waveform pattern 64 that precedes or succeeds in time series may be determined to be the maximal blood pressure.
  • the average value of the applied pressure corresponding to the maximum value that precedes in time series and the applied pressure corresponding to the maximum value that succeeds in time series may be determined to be the maximal blood pressure.
  • the waveform illustrated in FIG. 10 is not observed by a cuff method, but is observed when applying pressure to the radial artery 16 by locally pressing a skin area (body surface) positioned above the radial artery 16 , and measuring the change in volume of the blood vessel with each heartbeat using the small pressure sensor 12 .
  • the pressure (applied pressure) i.e., mean blood pressure 72
  • mean blood pressure 72 detected by the pressure sensor 12 when the oscillometric waveform 18 has the maximum amplitude
  • the applied pressure when an oscillometric waveform has the maximum amplitude is medically defined as the mean blood pressure.
  • FIGS. 11A to 11F are views illustrating the systolic waveform pattern 64 included in the oscillometric waveform 18 according to one embodiment of the invention.
  • the left side of FIGS. 11A to 11D indicates the relationship between the internal-external pressure difference based on the tube law and the cross-sectional area of the blood vessel in time series. Since a change in cross-sectional area differs depending on the internal-external pressure difference, the pressure detected by the pressure sensor 12 differs depending on the change range even if the change in pressure (pulse) is the same. Since the pressure applied to the blood vessel differs between the peripheral area and the center area of the pressure sensor 12 , the difference in change in pressure appears as a temporal difference.
  • the size of the waveform becomes equal due to a change, and is reversed.
  • the detected pressure differs between the peripheral area and the center area of the pressure sensor 12 even if the pressure is the same.
  • the peripheral area of the pressure sensor 12 has low sensitivity
  • the center area of the pressure sensor 12 has high sensitivity.
  • a change that occurs in time series is described below. As illustrated in FIG. 11A , since the blood vessel that comes in contact with the center area of the pressure sensor 12 is occluded when the applied pressure is high, a signal is not generated from the center area of the pressure sensor 12 , and a signal is generated from the peripheral area of the pressure sensor as a small waveform A- 1 according to the tube law.
  • the blood vessel that comes in contact with the center area of the pressure sensor 12 is opened to some extent when the applied pressure is reduced, and a signal is generated from the center area of the pressure sensor 12 as a small waveform B- 2 according to the tube law.
  • a signal is generated from the peripheral area of the pressure sensor as a medium waveform B- 1 according to the tube law.
  • the medium waveform B- 1 precedes the small waveform B- 2 . This is because vibrations applied to the peripheral area of the pressure sensor 12 start earlier than those applied to the center area.
  • the blood vessel that comes in contact with the center area of the pressure sensor 12 is further opened when the applied pressure is further reduced, and a signal is generated from the center area of the pressure sensor 12 as a medium waveform C- 2 according to the tube law.
  • a signal is generated from the peripheral area of the pressure sensor as a medium waveform C- 1 according to the tube law. Specifically, the waveforms of the center area and the peripheral area of the pressure sensor 12 become almost equal.
  • the blood vessel that comes in contact with the center area of the pressure sensor 12 is further opened when the applied pressure is further reduced, and a signal is generated from the center area of the pressure sensor 12 as a large waveform D- 2 according to the tube law.
  • a signal is generated from the peripheral area of the pressure sensor as a small waveform D- 1 according to the tube law.
  • FIG. 11E illustrates these waveforms in time series
  • FIG. 11F illustrates the actual waveform
  • FIG. 12 is a flowchart illustrating the entire operation (process) according to one embodiment of the invention. The entire operation (process) is described below with reference to FIG. 12 .
  • the blood pressure detection apparatus 2 starts to operate when a switch 66 of the control-display section 14 has been pressed (step S 10 ).
  • the CPU 56 instructs the press mechanism 10 to start a pressure-applying operation via the control signal line 30 .
  • the press mechanism 10 then activates the motor 24 and the pump 26 so that air is supplied to the expansion section 28 .
  • the CPU 56 starts measurement of the pressure detected by the pressure sensor 12 and input via the pressure signal lines 42 and 60 .
  • the CPU 56 determines whether or not the pressure detected by the pressure sensor 12 is equal to or greater than a preset value (e.g., 200 mmHg) (step S 20 ). When the CPU 56 has determined that the pressure detected by the pressure sensor 12 is less than 200 mmHg (No), the CPU 56 continues to determine whether or not the pressure detected by the pressure sensor 12 is equal to or greater than 200 mmHg. When the CPU 56 has determined that the pressure detected by the pressure sensor 12 is equal to or greater than 200 mmHg (Yes), the CPU 56 then performs a step S 30 .
  • a preset value e.g. 200 mmHg
  • the CPU 56 instructs the press mechanism 10 to stop the pressure-applying operation and start a pressure-reducing operation via the control signal line 30 (step S 30 ).
  • the pump 26 included in the press mechanism then stops the pressure-applying operation, and starts the pressure-reducing operation.
  • the pressure-reducing operation is performed at a constant rate of 3 mmHg per second.
  • the CPU 56 then starts measurement (700 times per second) of the oscillometric signal input from the signal line 58 (step S 40 ).
  • the oscillometric waveform 18 is obtained by arranging the measured values in time series.
  • the CPU 56 stores a signal received from the pressure sensor 12 in a memory (not shown) while sequentially receiving a signal from the pressure sensor 12 to generate the oscillometric waveform 18 .
  • the CPU 56 determines the shape of the oscillometric waveform 18 (step S 50 ). When the determined shape of the oscillometric waveform 18 is not the systolic waveform pattern 64 (see FIG. 10 ) (No), the CPU 56 determines the shape of the next oscillometric waveform 18 . When the determined shape of the oscillometric waveform 18 is the systolic waveform pattern 64 (Yes), the CPU 56 then performs a step S 60 .
  • the CPU 56 then stores the pressure (applied pressure) (i.e., systolic blood pressure 68 ) detected by the pressure sensor 12 which corresponds to the systolic waveform pattern 64 (step S 60 ).
  • the CPU 56 determines whether or not the oscillometric waveform 18 has the maximum amplitude (step S 70 ). When the CPU 56 has determined that the oscillometric waveform 18 does not have the maximum amplitude (No), the CPU 56 determines whether or not the next oscillometric waveform 18 has the maximum amplitude. When the CPU 56 has determined that the oscillometric waveform 18 has the maximum amplitude (Yes), the CPU 56 then performs a step S 80 .
  • the CPU 56 then stores the pressure (applied pressure) (i.e., mean blood pressure 72 ) detected by the pressure sensor 12 when the oscillometric waveform 18 has the maximum amplitude (mean blood pressure waveform 70 ) in the memory (step S 80 ).
  • the CPU 56 has thus determined the systolic blood pressure 68 and the mean blood pressure 72 .
  • the CPU 56 then stops the measurement of the oscillometric signal input via the signal line 58 (step S 90 ).
  • the CPU 56 instructs the press mechanism 10 to stop the pressure-reducing operation via the control signal line 30 .
  • the pump 26 included in the press mechanism then stops the pressure-reducing operation.
  • the CPU 56 then calculates the diastolic blood pressure (minimal blood pressure) from the systolic blood pressure 68 and the mean blood pressure 72 using the blood pressure calculation section (step S 100 ).
  • the CPU 56 then displays the systolic blood pressure 68 and the diastolic blood pressure on a display device 74 , and finishes the process (step S 110 ).
  • an accurate blood pressure can be quickly determined.
  • the blood pressure detection apparatus is used as a wearable sphygmomanometer that allows arbitrary blood pressure measurement, the blood pressure can be frequently measured without causing inconvenience to the user, so that the blood pressure can be monitored advantageously.
  • the applied pressure when the systolic waveform pattern 64 occurs is determined to be the maximal blood pressure while reducing the applied pressure has been described above.
  • the applied pressure when the systolic waveform pattern 64 occurs may be determined to be the maximal blood pressure while increasing the applied pressure.
  • the blood pressure calculation section may determine the pressure when a given waveform pattern appears in the waveform of the pulse waves obtained from the pressure sensor 12 when the artery is gradually occluded from an open state to be the systolic blood pressure (maximal blood pressure), and may determine the pressure when the waveform has the maximum amplitude to be the mean blood pressure.
  • FIG. 13 is a view illustrating a systolic waveform pattern included in an oscillometric waveform according to this modification.
  • FIG. 13 illustrates a pressure signal waveform 44 of pressure applied to the blood vessel (lower side), and a pulse waveform 76 detected when applying the pressure to the blood vessel (upper side).
  • a systolic waveform pattern 64 included in the pulse waveform 76 differs from other waveforms.
  • a maximum value among a plurality of maximum values that precedes the other maximum value(s) in time series i.e., when a lower pressure is applied by the press mechanism 10
  • the succeeding maximum value(s) in time series i.e., when a higher pressure is applied by the press mechanism 10
  • a maximum value among a plurality of maximum values that precedes the other maximum value(s) in time series is smaller than the succeeding maximum value(s) in time series (i.e., when a higher pressure is applied by the press mechanism 10 ).
  • the relationship between the maximum values of the systolic waveform pattern 64 differs from (is the reverse of) the relationship between the maximum values of the pulse waveform that precedes the systolic waveform pattern 64 . Therefore, the systolic waveform pattern 64 can be determined based on whether or not the relationship between the maximum values of the waveform has changed.
  • the pressure of the pressure signal waveform 44 corresponding to the systolic waveform pattern 64 is 135 mmHg, which is very close to the maximal blood pressure (136 mmHg) measured by another sphygmomanometer. Therefore, the maximal blood pressure can be conveniently determined without increasing and decreasing the applied pressure as in the case of using a normal sphygmomanometer.
  • the blood pressure calculation section determines the pressure when the waveform of the pulse waves obtained from the pressure sensor 12 when the artery is gradually opened from an occlusion state has the maximum amplitude to be the mean blood pressure.
  • the blood pressure calculation means may determine the pressure when the waveform has the maximum value to be the mean blood pressure.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • Pathology (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Physics & Mathematics (AREA)
  • Biophysics (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Cardiology (AREA)
  • Vascular Medicine (AREA)
  • Ophthalmology & Optometry (AREA)
  • Physiology (AREA)
  • Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
US13/191,584 2010-08-02 2011-07-27 Blood pressure detection apparatus and blood pressure detection method Abandoned US20120029366A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010-173377 2010-08-02
JP2010173377A JP5732692B2 (ja) 2010-08-02 2010-08-02 血圧検出装置及び血圧検出方法

Publications (1)

Publication Number Publication Date
US20120029366A1 true US20120029366A1 (en) 2012-02-02

Family

ID=45527444

Family Applications (1)

Application Number Title Priority Date Filing Date
US13/191,584 Abandoned US20120029366A1 (en) 2010-08-02 2011-07-27 Blood pressure detection apparatus and blood pressure detection method

Country Status (3)

Country Link
US (1) US20120029366A1 (enrdf_load_stackoverflow)
JP (1) JP5732692B2 (enrdf_load_stackoverflow)
CN (2) CN104224152A (enrdf_load_stackoverflow)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150133791A1 (en) * 2012-05-29 2015-05-14 National University Corporation Kochi University Artery visualization device and artery imaging device
US20150265214A1 (en) * 2014-03-24 2015-09-24 Samsung Electronics Co., Ltd. Adjustable sensor support structure for optimizing skin contact
CN109069027A (zh) * 2016-04-28 2018-12-21 欧姆龙健康医疗事业株式会社 压力脉搏波传感器、脉搏波检测装置和生物信息测定装置

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105078432A (zh) * 2014-05-14 2015-11-25 旺玖科技股份有限公司 测量血压的装置和方法
CN104434053A (zh) * 2014-07-02 2015-03-25 许建平 一种电子检测装置
CN110381822B (zh) * 2017-03-15 2022-09-13 欧姆龙株式会社 血压测定装置和存储介质
TWI731339B (zh) 2018-06-11 2021-06-21 當代漢雲企業有限公司 脈診量測裝置及方法
KR20210117693A (ko) * 2020-03-20 2021-09-29 (주)참케어 혈압측정 시스템 및 이를 이용한 혈압 측정 방법

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4754761A (en) * 1985-07-05 1988-07-05 Critikon, Inc. Automated mean arterial blood pressure monitor with data enhancement
US4830019A (en) * 1986-06-12 1989-05-16 Omron Tateisi Electronics Co. Electronic blood pressure meter
US5193548A (en) * 1989-11-08 1993-03-16 Omron Corporation Electronic blood pressure meter
US5265011A (en) * 1989-04-03 1993-11-23 Eastern Medical Testing Services, Inc. Method for ascertaining the pressure pulse and related parameters in the ascending aorta from the contour of the pressure pulse in the peripheral arteries
US20020026121A1 (en) * 1999-04-21 2002-02-28 Jie Kan Noninvasive blood pressure measuring method and apparatus

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH053858A (ja) * 1991-06-28 1993-01-14 Colleen Denshi Kk 血圧モニタ装置
JP3002600B2 (ja) * 1992-03-21 2000-01-24 日本コーリン株式会社 血圧モニタ装置
JP3210737B2 (ja) * 1992-08-26 2001-09-17 松下電工株式会社 電子血圧計
EP0627190B1 (en) * 1993-05-17 2000-04-26 Omron Corporation Device to measure vascular function
JP3534887B2 (ja) * 1995-04-19 2004-06-07 株式会社エー・アンド・デイ 血圧計
WO2000003636A1 (fr) * 1998-07-17 2000-01-27 Citizen Watch Co., Ltd. Tensiometre electronique et procede de mesure de la tension arterielle
JP4437196B2 (ja) * 1999-04-02 2010-03-24 テルモ株式会社 血圧計
CN1163191C (zh) * 1999-04-21 2004-08-25 陆渭明 无创伤连续测量血压的方法和装置
JP2003284696A (ja) * 2002-03-28 2003-10-07 Omron Corp 電子血圧計および電子血圧計の血圧測定方法
JP2006280485A (ja) * 2005-03-09 2006-10-19 Motoharu Hasegawa 血圧検出装置、血圧検出方法、血圧検出プログラム及び血圧検出歪みセンサ
CN100488446C (zh) * 2005-07-14 2009-05-20 优盛医学科技股份有限公司 智能型加压控制装置
JP5043707B2 (ja) * 2008-02-12 2012-10-10 テルモ株式会社 血圧測定装置およびその制御方法
JP5189390B2 (ja) * 2008-03-26 2013-04-24 フクダ電子株式会社 データ処理装置、血圧計及びデータ処理プログラム

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4754761A (en) * 1985-07-05 1988-07-05 Critikon, Inc. Automated mean arterial blood pressure monitor with data enhancement
US4830019A (en) * 1986-06-12 1989-05-16 Omron Tateisi Electronics Co. Electronic blood pressure meter
US5265011A (en) * 1989-04-03 1993-11-23 Eastern Medical Testing Services, Inc. Method for ascertaining the pressure pulse and related parameters in the ascending aorta from the contour of the pressure pulse in the peripheral arteries
US5193548A (en) * 1989-11-08 1993-03-16 Omron Corporation Electronic blood pressure meter
US20020026121A1 (en) * 1999-04-21 2002-02-28 Jie Kan Noninvasive blood pressure measuring method and apparatus

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150133791A1 (en) * 2012-05-29 2015-05-14 National University Corporation Kochi University Artery visualization device and artery imaging device
US10349886B2 (en) * 2012-05-29 2019-07-16 National University Corporation Kochi University Artery visualization device and artery imaging device
US20150265214A1 (en) * 2014-03-24 2015-09-24 Samsung Electronics Co., Ltd. Adjustable sensor support structure for optimizing skin contact
CN109069027A (zh) * 2016-04-28 2018-12-21 欧姆龙健康医疗事业株式会社 压力脉搏波传感器、脉搏波检测装置和生物信息测定装置

Also Published As

Publication number Publication date
CN104224152A (zh) 2014-12-24
CN102379689A (zh) 2012-03-21
CN102379689B (zh) 2015-10-07
JP5732692B2 (ja) 2015-06-10
JP2012029967A (ja) 2012-02-16

Similar Documents

Publication Publication Date Title
US6443905B1 (en) Method and arrangement for blood pressure measurement
US20120029366A1 (en) Blood pressure detection apparatus and blood pressure detection method
EP1011434B1 (en) Method and arrangement for blood pressure measurement
JP5098721B2 (ja) 血圧測定装置、血圧導出プログラムおよび血圧導出方法
TWI258359B (en) Apparatus for evaluating cardiovascular functions
US6824519B2 (en) Heart-sound detecting apparatus
US6610017B2 (en) Continuous blood-pressure monitoring apparatus
CN110301906A (zh) 无创血压测量方法和装置
US20050171443A1 (en) Apparatus and method for non-invasive monitoring of cardiac performance
EP1332715A2 (en) Arteriosclerosis inspecting apparatus
US7270636B2 (en) Apparatus and method for pulse detection
CN104042200B (zh) 一种逐拍动脉血压的无创监测装置及其方法
CA2604337A1 (en) System and method for non-invasive cardiovascular assessment from supra-systolic signals obtained with a wideband external pulse transducer in a blood pressure cuff
EP1264573A2 (en) Blood-pressure measurement apparatus capable of heart function assessment
JP2004000422A (ja) 波形解析機能付き血圧測定装置
US20040171941A1 (en) Blood flow amount estimating apparatus
KR102570356B1 (ko) 개선된 혈압 측정 시스템
US20040077959A1 (en) Vital-information obtaining apparatus
JPH07308295A (ja) 血圧測定装置
JP2664918B2 (ja) 血圧モニタ装置
JP2001137203A (ja) 血圧監視装置
JP2798677B2 (ja) 血圧モニタ装置
JP2002136489A (ja) 血圧測定装置および脈波伝播速度情報測定装置
JP3662683B2 (ja) 心拍出量推定装置
JP2001309894A (ja) 末梢静脈圧測定装置及び末梢静脈圧測定方法

Legal Events

Date Code Title Description
AS Assignment

Owner name: SEIKO EPSON CORPORATION, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:YOKOYAMA, TOSHIHIKO;TOCHIKUBO, OSAMU;SIGNING DATES FROM 20110608 TO 20110714;REEL/FRAME:026655/0751

Owner name: PUBLIC UNIVERSITY CORPORATION YOKOHAMA CITY UNIVER

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:YOKOYAMA, TOSHIHIKO;TOCHIKUBO, OSAMU;SIGNING DATES FROM 20110608 TO 20110714;REEL/FRAME:026655/0751

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION